Intel
Intel Core i5-8400
Six cores in a 65 W, box-cooler part - the chip that ended Intel's four-core mainstream era. Its 2.8 GHz base looks weak on paper but it holds around 3.8 GHz across all six cores, and it remains the cheapest sane six-core buy on LGA1151.
Pros
- Six cores at roughly 3.8 GHz all-core, 4.0 GHz on one core
- 65 W base power with a stock cooler in the box - fits small cases and cheap PSUs
- 9 MB L3 and DDR4-2666 official support
- UHD Graphics 630 for display output, QuickSync and 4K decode
- Supported by Windows 11, unlike the 6th and 7th gen parts
Cons
- Locked multiplier, and the 2.8 GHz base is what you get if cooling or board power limits are poor
- No Hyper-Threading - six threads shows up quickly in encoding, rendering and streaming
- No memory overclocking outside Z370/Z390, and DDR4-2666 is the official cap
- Requires a 300-series chipset; it will not post in a 100/200-series board
Below average
Computed from specs & benchmarks via our public methodology.
Full specifications
Everything we track for the Intel Core i5-8400
General
- Announced
- 2017
- Socket
- LGA1151-v2
- Process
- 14 nm
- Base TDP
- 65 W
- Unlocked multiplier
- No
- Cooler included
- Yes
Cores & Clocks
- Cores
- 6
- Performance cores
- 6
- Efficiency cores
- 0
- Threads
- 6
- Base clock
- 2.8 GHz
- Boost clock
- 4 GHz
- L2 cache
- 2 MB
- L3 cache
- 9 MB
Integrated GPU
- iGPU
- Intel UHD Graphics 630
- iGPU clock
- 1,050 MHz
Memory
- Memory support
- DDR4-2666
- Max memory
- 64 GB
- Memory channels
- 2
Platform
- PCIe version
- 3
- CPU PCIe lanes
- 16
Benchmarks
- Geekbench 6 (single)
- 1,370
- Geekbench 6 (multi)
- 4,900
- Cinebench R23 (single)
- 1,150
- Cinebench R23 (multi)
- 6,400
- PassMark
- 9,200
Quick answers
Is the Intel Core i5-8400 good in 2026?
The Intel Core i5-8400 earns an Inno Score of 29/100 (“Below average”) based on its specs and benchmark results. Six cores in a 65 W, box-cooler part - the chip that ended Intel's four-core mainstream era. Its 2.8 GHz base looks weak on paper but it holds around 3.8 GHz across all six cores, and it remains the cheapest sane six-core buy on LGA1151.
What are the key specs of the Intel Core i5-8400?
Cores: 6 · Threads: 6 · Boost clock: 4 GHz · Socket: LGA1151-v2
What are the closest alternatives to the Intel Core i5-8400?
Its closest rivals on InnoReviews are Intel Core i7-5820K, Intel Core i5-9400F, Intel Core i7-5930K — open the comparison pages for a spec-by-spec breakdown.